/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.api;

import org.apache.flink.annotation.PublicEvolving;

import java.util.Optional;

/** The {@link PlannerConfig} holds parameters to configure the behavior of queries. */
@PublicEvolving
public interface PlannerConfig {

    PlannerConfig EMPTY_CONFIG = new PlannerConfig() {};

    @SuppressWarnings("unchecked")
    default <T extends PlannerConfig> Optional<T> unwrap(Class<T> type) {
        if (type.isInstance(this)) {
            return Optional.of((T) this);
        } else {
            return Optional.empty();
        }
    }
}
